Python String zfill() Method

The zfill() method pads a string on the left with zeros (0) until it reaches a specified width. It is useful for formatting numeric strings with fixed width (e.g., “001", "002", …, "010".

Syntax

string.zfill(width)

Parameters

No parameters.

Return Value

Returns a new string padded with zeros on the left to meet the specified width.

If the width is smaller than or equal to the string length, the original string is returned.

Examples

Zero Padding a String in Python

text = "35"
print(text.zfill(5)) # Output: 00035

With Negative or Positive Sign

If the string starts with a positive or negative sign, the zeros are added after the sign.

text = "-35"
print(text.zfill(5)) # Output: -00035

text2 = "+35"
print(text2.zfill(5)) # Output: +0035

Width Smaller Than or Equal to String Length

If the width is smaller than or equal to the string length, the original string is returned.

text = "12345"
print(text.zfill(3)) # Output: 12345